Vibronic Problem For the Relaxed Excited State of the F-center in Alkali Halides. I. Vibronic Energy Schemes

The relaxed excited state of the F -center in alkali halides is studied theoretically as a vibronic system consisting of 2 s and 2 p electronic states interacting with local mode phonons. The model Hamiltonian is introduced which contains the s -, p - and d -like interaction modes. The vibronic problem for the s - and p -modes is solved numerically in the case of intermediate coupling strength and the energy schemes thus obtained are presented.